Center-square and bevel



(No Model.)

.J. W. ROMANS.

CENTER SQUARE AND BEVEL. I N0. 271,128. Patented Ja-n.23,18 83.

E1191. Fig.2.

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NITED STATES PATENT Erich.

JOHN \V. ROMANS, OF CHELSEA, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO JOHN MOGLELLAN, OF VALPARAISO, INDIANA.

CENTER-SQUARE AND BEVEL.

SPECIFICATION forming part of Letters Patent No. 271,128, dated January 23, 1883, Application filed November 16, 1881. (No model.) V

To all whom it may concern:

Be it known thatI, JOHN W. RoMANs, a citizen of the United States, residing at Chelsea, in the county of Suffolk and State of Mas- 5 sachusetts, have invented a new and useful Center-Square and Bevel, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to an instrument which may be employed for the various uses of a square, center-square, and bevel, technically so called; and it consists in a square having, in combination therewith, as hereinafter set forth, a rule, bar, or blade which may 1 be set and held in such positions relative to the square to adapt the instrument for the uses above named.

In the drawings, Figurel shows an instrument embodying my invention, the rule, bar,

or blade being set in such position relative to the square as to determine the center ofa circular piece, indicated by the dotted line. Fig.2 is

an edge view ofsaid instrument. Fig. 3 shows the screw and thumb-nut; and Fig. 4. shows 2 the instrument, a part of oneof the limbs of the square being broken away and the blade set in relation to the square to form a bevel.

The square consists of the two limbs A and B, the one, A, being formed in one piece, as is common. The limb B consists of two parallel parts, a and b, there being a space between said parts, in which a blade, 0, fits in such a manner that it may be slid or moved about in any direction in a plane'parallel to the plane 5 of either of its two opposite broad surfaces or ofthe broad surfaces of the square. The blade (J has a slot, 0, in which is the shank ofa screw,

(1, andthe part a of the limb B has also aslot for this screw, as shown. The screw (1 has a 40 head, 6, which may be thrust through a hole,

f, in the part b of the limb B, but is made angnlar, so that it will slide in agroove,g,in the inner side of the part b and be kept from turning when the thumb-nut h is revolved. The

5 head c bears against one side of the blade 0,

so that by means of the screw (1 and the thumbnut h, which bears against the outer surface of the part a, the blade may be clamped firmly to the part a, and hence to the square in any required position. At the angle formed by the limbsAand B of the square there is a shoulder, 1', which is at the end of the space between the parts a and b. This shoulder t' is at an angle of forty-five degrees with the outer edge faces of the limbs of the square, so that an edge of the blade 0 bearing against and parallel to the shoulder will extend through the center of a circular piece, against the periphery of which the limbs of the square bear. By making a short mark along the edge of the blade when the instrument is so adjusted and placed and then moving the instrument to another position on the circle and making another mark by the edge of the blade the crossing of the two lines will determine the center, as illustrated by the dotted lines in Fig 1. By sliding the blade endwise the instrument will be adapted to larger or smaller circles, as will be readily understood.

It will not be needfnl to specify or set forth in detail any ofthe many other useful applications of the instrument as a square or bevel, such being obvious to a mechanic and will be appreciated by the same, particularly in carpentryandpattern-making. However,theposition of the blade, as shown in Fig. 4, illustrates how the blade may-be moved about to form bevels having different angles.

Though the particular arrangement and construction shown of parts of the device are desirable, yet I would not confine my invention to them as faras relates to the method of clamping the blade to the square, for other ways of clamping might be used-as, for instance, clamping the blade against the outer surface of one of the limbs of the square, there being a suitableshoulder, i, formed on the outside of the square.

I claim as my invention- 1. In combination with a square having a 0 space extending through the length of a limb of the square and between parts thereof, and having a shoulder, i, formed at an angle of forty-five degrees with each of the outer edge faces of the square, at the end of said space, 5 and at the angle of the square, as specified, a blade having a straight edge and adapted to swing about and to he slid in the direction of its ownlength andin the direction of the length of said limb of the square, substantially as and for the purposes set forth.

2. In combination, a blade having astraight 2 1 ensue edge and a slot, 0, a square having a space he a slot in one of said parts, and a groove in the [O tween parts of one of its limbs to receive said inner surface of the other of said parts, a blade blade and a slot in one of said parts, a shoul- I having a slot; and a screw and thumb-nut, the

der, i, at the angle of the square and formed head of the screw adapted to slide in said at an angle of forty-five degrees with each of groove substantially as described.

the outer edge faces of the square, and a pin JOHN W. ROMANS.

or screw, d, substantially as set forth. i \Vitnesses:

3. In combination a square having a space LOUIS COHEN; to receive a blade between parts'of one limb, EDW. DUMMER. 

